Summary
Apache Polaris accepts literal * characters in namespace and table names. When it later builds temporary S3 access policies for delegated table access, those same characters appear to be reused unescaped in S3 IAM resource patterns and s3:prefix conditions.
In S3 IAM policy matching, * is treated as a wildcard rather than as ordinary text. That means temporary credentials issued for one crafted table can match the storage path of a different table.
In private testing against Polaris 1.4.0 using Polaris' AWS S3 temporary-credential path on both MinIO and real AWS S3, credentials returned for crafted tables such as f*.t1, f*.*, *.*, and foo.* could reach other tables' S3 locations.
The confirmed behavior includes:
- reading another table's metadata control file ([Iceberg metadata JSON]);
- listing another table's exact S3 table prefix ([table prefix]);
- and, when write delegation was returned for the crafted table, creating and deleting an object under another table's exact S3 table prefix.
A control case using ordinary different names did not allow the same cross-table access.
A least-privilege AWS S3 variant was also confirmed in which the attacker principal had no Polaris permissions on the victim table and only the minimal permissions required to create and use a crafted wildcard table (namespace-scoped TABLE_CREATE and TABLE_WRITE_DATA on *). In that setup, direct Polaris access to foo.t1 remained forbidden, but the attacker could still create and load *.*, receive delegated S3 credentials, and use those credentials to list, read, create, and delete objects under foo.t1.
In Iceberg, the metadata JSON file is a control file: it tells readers which data files belong to the table, which snapshots exist, and which table version to read. So unauthorized access to it is already a meaningful confidentiality problem. The confirmed write-capable variant means the issue is not limited to disclosure.
Impact
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
CVE-2026-42810 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.4.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-42810? CVE-2026-42810 is a critical-severity improper input validation vulnerability in org.apache.polaris:polaris-core (maven), affecting versions < 1.4.1. It is fixed in 1.4.1. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is CVE-2026-42810? CVE-2026-42810 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.apache.polaris:polaris-core are affected by CVE-2026-42810? org.apache.polaris:polaris-core (maven) versions < 1.4.1 is affected.
- Is there a fix for CVE-2026-42810? Yes. CVE-2026-42810 is fixed in 1.4.1. Upgrade to this version or later.
- Is CVE-2026-42810 exploitable, and should I be worried? Whether CVE-2026-42810 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-42810 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-42810? Upgrade
org.apache.polaris:polaris-coreto 1.4.1 or later.